YM155 inhibits topoisomerase function

Therapeutic Efficacy of YM155 to Regulate an Epigenetic Enzyme in Major Subtypes of RCC

Renal cell carcinoma (RCC) is the most common type of kidney cancer and includes more than 10 subtypes. Compared to the intensively investigated clear cell RCC (ccRCC), the underlying mechanisms and treatment options of other subtypes, including papillary RCC (pRCC) and chromogenic RCC (chRCC), are limited. In this study, we analyzed the public databases for ccRCC, pRCC, and chRCC and found that BIRC5 was commonly overexpressed in a large cohort of pRCC and chRCC patients as well as ccRCC and was closely related to the progression of RCCs. We investigated the potential of BIRC5 as a therapeutic target for these three types of RCCs. Loss and gain of function studies showed the critical role of BIRC5 in cancer growth. YM155, a BIRC5 inhibitor, induced a potent tumor-suppressive effect in the three types of RCC cells and xenograft models. To determine the mechanism underlying the anti-tumor effects of YM155, we examined epigenetic modifications in the BIRC5 promoter and found that histone H3 lysine 27 acetylation (H3K27Ac) was highly enriched on the promoter region of BIRC5. Chromatin-immunoprecipitation analysis revealed that H3K27Ac enrichment was significantly decreased by YM155. Immunohistochemistry of xenografted tissue showed that overexpression of BIRC5 plays an important role in malignancy in RCC. Furthermore, high expression of P300 was significantly associated with the progression of RCC. Our findings demonstrate the P300-H3K27Ac-BIRC5 cascade in three types of RCC and provide a therapeutic path for future research on RCC.

Targeting survivin for cancer therapy: Strategies, small molecule inhibitors and vaccine based therapeutics in development

Survivin is a member of the family of inhibitors of apoptosis proteins (IAPs). It is involved in the normal mitotic process and acts as an anti-apoptotic molecule. While terminally differentiated normal tissues lack survivin, several human malignancies have significant protein levels. Resistance to chemotherapy and radiation in tumor cells is associated with survivin expression. Decreased tumor development, apoptosis, and increased sensitivity to chemotherapy and radiation are all effects of downregulating survivin expression or activity. As a prospective cancer treatment, small molecules targeting the transcription and translation of survivin and molecules that can directly bind with the survivin are being explored both in pre-clinical and clinics. Pre-clinical investigations have found and demonstrated the effectiveness of several small-molecule survivin inhibitors. Unfortunately, these inhibitors have also been shown to have off-target effects, which could limit their clinical utility. In addition to small molecules, several survivin peptide vaccines are currently under development. These vaccines are designed to elicit a cytotoxic T-cell response against survivin, which could lead to the destruction of tumor cells expressing survivin. Some survivin-based vaccines are advancing through Phase II clinical studies. Overall, survivin is a promising cancer drug target. However, challenges still need to be addressed before the survivin targeted therapies can be widely used in the clinics.

Senescence-based colorectal cancer subtyping reveals distinct molecular characteristics and therapeutic strategies

Cellular senescence has been listed as a hallmark of cancer, but its role in colorectal cancer (CRC) remains unclear. We comprehensively evaluated the transcriptome, genome, digital pathology, and clinical data from multiple datasets of CRC patients and proposed a novel senescence subtype for CRC. Multi-omics data was used to analyze the biological features, tumor microenvironment, and mutation landscape of senescence subtypes, as well as drug sensitivity and immunotherapy response. The senescence score was constructed to better quantify senescence in each patient for clinical use. Unsupervised learning revealed three transcriptome-based senescence subtypes. Cluster 1, characterized by low senescence and activated proliferative pathways, was sensitive to chemotherapeutic drugs. Cluster 2, characterized by intermediate senescence and high immune infiltration, exhibited significant immunotherapeutic advantages. Cluster 3, characterized by high senescence, high immune, and stroma infiltration, had a worse prognosis and maybe benefit from targeted therapy. We further constructed a senescence scoring system based on seven senescent genes through machine learning. Lower senescence scores were highly predictive of longer disease-free survival, and patients with low senescence scores may benefit from immunotherapy. We proposed the senescence subtypes of CRC and our findings provide potential treatment interventions for each CRC senescence subtype to promote precision treatment.

Survivin Small Molecules Inhibitors: Recent Advances and Challenges

Survivin, as a member of the inhibitor of apoptosis proteins (IAPs) family, acts as a suppressor of apoptosis and plays a central role in cell division. Survivin has been considered as an important cancer drug target because it is highly expressed in many types of human cancers, while it is effectively absent from terminally differentiated normal tissues. Moreover, survivin is involved in tumor cell resistance to chemotherapy and radiation. Preclinically, downregulation of survivin expression or function reduced tumor growth induced apoptosis and sensitized tumor cells to radiation and chemotherapy in different human tumor models. This review highlights the role of survivin in promoting cellular proliferation and inhibiting apoptosis and summarizes the recent advances in and challenges of developing small-molecule survivin inhibitors.

YM155 inhibits neuroblastoma growth through degradation of MYCN: A new role as a USP7 inhibitor

Amplification of the MYCN gene (MNA) is observed in approximately 25 to 35% of neuroblastoma patients, and is a well-recognized marker of tumor aggressiveness and poor outcome. Targeting MYCN is a novel therapy strategy to induce tumor regression. Here, we discovered that a BIRC5/Survivin inhibitor, YM155, specifically inhibits MNA neuroblastoma cell growth in vitro. We found that YM155 promotes MYCN degradation in MNA cells. Further, we found that YM155 inhibits USP7 deubiquitinase activity in vitro, using Ub-aminomethylcoumarin (Ub-AMC) as substrate. Results from in vivo studies further demonstrated that YM155 significantly inhibited the tumor growth in MNA neuroblastoma xenograft model. Our data support a novel mechanism of action of YM155 in inhibition of growth of cancer cells through inducing MYCN degradation by inibition of activity of deubiquitinase like USP7.

YM155 Induces DNA Damage and Cell Death in Anaplastic Thyroid Cancer Cells by Inhibiting DNA Topoisomerase IIα at the ATP-Binding Site

Anaplastic thyroid cancer (ATC) is among the most aggressive of human cancers, and currently there are few effective treatments for most patients. YM155, first identified as a survivin inhibitor, was highlighted in a high-throughput screen performed by the National Cancer Institute, killing ATC cells in vitro and in vivo. However, there was no association between survivin expression and response to YM155 in clinical trials, and YM155 has been mostly abandoned for development despite favorable pharmacokinetic and toxicity profiles. Currently, alternative mechanisms are being explored for YM155 by a number of groups. In this study, ATC patient samples show overexpression of topoisomerase Top2α compared with benign thyroid samples and to differentiated thyroid cancers. ATC cell lines that overexpress Top2α are more sensitive to YM155. We created a YM155-resistant cell line, which shows decreased expression of Top2α and is resensitized with Top2α overexpression. Molecular modeling predicts binding for YM155 in the Top2α ATP-binding site and identifies key amino acids for YM155-Top2α interaction. A Top2α mutant abrogates the effect of YM155, confirming the contribution of Top2α to YM155 mechanism of action. Our results suggest a novel mechanism of action for YM155 and may represent a new therapeutic approach for the treatment of ATC.

The Role of Survivin and Transcription Factor FOXP1 in Scarring After Glaucoma Surgery

Purpose

This study aims to elucidate the role and mechanism of survivin and FOXP1 in scarring after glaucoma surgery and to evaluate the prevention and treatment of excessive wound healing and scar formation in an in vitro model of glaucoma filtration surgery.

Methods

Human Tenon's capsule fibroblasts (HTFs) were used with TGF-β to establish an in vitro cell model after glaucoma, observe survivin expression in the cell model, and observe HTFs proliferation after treatment with survivin inhibitor YM155 and the expression of α-SMA and collagen type I. In addition, the effects of survivin and cell proliferation in HTFs after knockdown of FOXP1 were observed by Western blot analysis.

Results

Survivin was upregulated in HTFs after glaucoma surgery, and it could promote the cell proliferation of HTFs. After treatment with its inhibitor YM155, the cell proliferation of HTFs was inhibited, and the expression of α-SMA and collagen type I were decreased. The results showed that in knockdown of FOXP1, the expression of survivin was downregulated, and the cell proliferation of HTFs was significantly reduced.

Conclusions

This study demonstrates that targeting survivin with an inhibitory YM155 reduced fibrosis and the extracellular matrix (ECM), and it was regulated by the FOXP1 transcription factor. These results suggest that survivin could be a potential target for treating scar formation after glaucoma surgery.

Translational Relevance

Together with the results from previous survivin and FOXP1 preclinical studies, these data support the evaluation of this gene therapy candidate in clinical trials as a potential durable treatment for antiscarring of glaucoma surgery.

Synthesis and biological evaluation of selective survivin inhibitors derived from the MX-106 hydroxyquinoline scaffold

The survivin (BIRC5) expression is very low in normal differentiated adult tissues, but it is one of the most widely upregulated genes in tumor cells. The overexpression of survivin in many cancer types has been positively correlated with resistance to chemotherapy, tumor metastasis, and poor patient survival. Survivin is considered to be a cancer specific biomarker and serves as a potential cancer drug target. In this report, we describe the design and syntheses of a series of novel selective survivin inhibitors based on the hydroxyquinoline scaffold from our previously reported lead compound MX-106. The best compound identified in this study is compound 12b. In vitro, 12b inhibited cancer cell proliferation with an average IC₅₀ value of 1.4 μM, using a panel of melanoma, breast, and ovarian cancer cell lines. The metabolic stability of 12b improved over MX-106 by 1.7-fold (88 vs 51 min in human microsomes). Western blot analyses demonstrated that treatments with 12b selectively decreased survivin protein levels, but negligibly affected other closely related members in the IAP family proteins, and strongly induced cancer cell apoptosis. In vivo, compound 12b effectively inhibited melanoma tumor growth when tested using a human A375 melanoma xenograft model. Further evaluation using an aggressive, orthotopic ovarian cancer mouse model showed that 12b was highly efficacious in suppressing both primary tumor growth in ovaries and tumor metastasis to multiple peritoneal organs. Collectively, results in this study strongly suggest that the hydroxyquinoline scaffold, represented by 12b and our earlier lead compound MX-106, has abilities to selectively target survivin and is promising for further preclinical development.

Survivin Expression Is Differentially Regulated by a Selective Cross-talk between RBM38 and miRNAs let-7b or miR-203a

RNA-binding motif 38 (RBM38) is a member of a protein family with a highly conserved RNA-binding motif and has been shown to regulate mRNA processing, stability, and translation. Survivin is an essential modulator of apoptotic and nonapoptotic cell death as well as a stress responder. Survivin mRNA is the fourth most frequently overexpressed transcript in the human cancer transcriptome, and its aberrant expression is associated with chemo-/radioresistance and poor prognosis. In this study, we examined whether survivin expression is regulated by RBM38. RBM38 bound to survivin 3'-untranslated region and suppressed miRNA let-7b from binding to and degrading survivin mRNA, leading to increased survivin expression. RBM38 interacted with argonaute-2 (AGO2) and facilitated miR-203a-mediated degradation of survivin mRNA, leading to decreased survivin expression. Due to the abundance of let-7b over miR-203a, RBM38 ultimately increased survivin expression in HCT116 and MCF7 cells. In addition, Ser-195 in RBM38 interacted with Glu-73/-76 in AGO2, and Pep8, an eight-amino acid peptide spanning the region of Ser-195 in RBM38, blocked the RBM38-AGO2 interaction and inhibited miR-203a-mediated mRNA degradation, leading to enhanced survivin expression. Furthermore, Pep8 cooperated with YM155, an inhibitor of survivin, to suppress tumor spheroid growth and viability. Pep8 sensitized tumor cells to YM155-induced DNA damage in an RBM38-dependent manner. Together, our data indicate that RBM38 is a dual regulator of survivin and that Pep8/YM155 may be therapeutically explored for tumor suppression. SIGNIFICANCE: These findings show that RBM38 exerts opposing effects on survivin expression via two miRNAs, and disruption of the RBM38-AGO2 complex by an eight-amino acid peptide sensitizes tumor spheroids to survivin inhibitor YM155.

YM155 Inhibits NleB and SseK Arginine Glycosyltransferase Activity

The type III secretion system effector proteins NleB and SseK are glycosyltransferases that glycosylate protein substrates on arginine residues. We conducted high-throughput screening assays on 42,498 compounds to identify NleB/SseK inhibitors. Such small molecules may be useful as mechanistic probes and may have utility in the eventual development of anti-virulence therapies against enteric bacterial pathogens. We observed that YM155 (sepantronium bromide) inhibits the activity of Escherichia coli NleB1, Citrobacter rodentium NleB, and both Salmonella enterica SseK1 and SseK2. YM155 was not toxic to mammalian cells, nor did it show cross-reactivity with the mammalian O-linked N-acetylglucosaminyltransferase (OGT). YM155 reduced Salmonella survival in mouse macrophage-like cells but had no direct impact on bacterial growth rates, suggesting YM155 may have utility as a potential anti-virulence inhibitor.

Ym155 Induces Oxidative Stress-Mediated DNA Damage and Cell Cycle Arrest, and Causes Programmed Cell Death in Anaplastic Thyroid Cancer Cells

Anaplastic thyroid cancer (ATC) is one of the most lethal malignancies with a median survival time of about 4 months. Currently, there is no effective treatment, and the development of new therapies is an important and urgent issue for ATC patients. YM155 is a small molecule that was identified as the top candidate in a high-throughput screen of small molecule inhibitors performed against a panel of ATC cell lines by the National Cancer Institute. However, there were no follow-up studies investigating YM155 in ATC. Here, we determined the effects of YM155 on ATC and human primary benign thyroid cell (PBTC) survival with alamarBlue assay. Our data show that YM155 inhibited proliferation of ATC cell lines while sparing normal thyroid cells, suggesting a high therapeutic window. YM155-induced DNA damage was detected by measuring phosphorylation of γ-H2AX as a marker for DNA double-strand breaks. The formamidopyrimidine-DNA glycosylase (FPG)-modified alkaline comet assay in conjunction with reactive oxygen species (ROS) assay and glutathione (GSH)/glutathione (GSSG) assay suggests that YM155-mediated oxidative stress contributes to DNA damage. In addition, we provide evidence that YM155 causes cell cycle arrest in S phase and in the G2/M transition and causes apoptosis, as seen with flow cytometry. In this study, we show for the first time the multiple effects of YM155 in ATC cells, furthering a potential therapeutic approach for ATC.

YM155 and BIRC5 downregulation induce genomic instability via autophagy-mediated ROS production and inhibition in DNA repair

Activation of autophagy plays a critical role in DNA repair, especially for the process of homologous recombination. Despite upregulation of autophagy promotes both the survival and the death of cells, the pathways that govern the pro-cell death effects of autophagy are still incompletely understood. YM155 is originally developed as an expression suppressant of BIRC5 (an anti-apoptotic molecule) and it has reached Phase I/II clinical trials for the treatment of variety types of cancer. However, the target-specificity of YM155 has recently been challenged as several studies reported that YM155 exhibits direct DNA damaging effects. Recently, we discovered that BIRC5 is an autophagy negative-modulator. Using function-comparative analysis, we found in the current study that YM155 and BIRC5 siRNA both induced early "autophagy-dependent ROS production-mediated" DNA damage/strand breaks and concurrently downregulated the expression of RAD54L, RAD51, and MRE11, which are molecules known for their important roles in homologous recombination, in human cancer (MCF7, MDA-MB-231, and SK-BR-3) and mouse embryonic fibroblast (MEF) cells. Similar to the effects of YM155 and BIRC5 siRNA, downregulation of RAD54L and RAD51 by siRNA induced autophagy and DNA damage/strand breaks in cells, suggesting YM155/BIRC5 siRNA might also induce autophagy partly through RAD54L and RAD51 downregulations. We further observed that prolonged YM155 and BIRC5 siRNA treatment induced autophagic vesicle formation proximal to the nucleus and triggered DNA leakage. In conclusion, our findings reveal a novel mechanism of action of YM155 (i.e. induces autophagy-dependent ROS production-mediated DNA damage) in cancer cells and show the functional complexity of BIRC5 and autophagy involving the modulation of genome stability, highlighting that upregulation of autophagy is not always beneficial to the DNA repair process. Our findings can aid the development of a variety of BIRC5-directly/indirectly targeted anticancer therapies that are currently under pre-clinical and clinical investigations.

Effect of Sepatronium Bromide (YM-155) on DNA Double-Strand Breaks Repair in Cancer Cells

Survivin, as an antiapoptotic protein often overexpressed in cancer cells, is a logical target for potential cancer treatment. By overexpressing survivin, cancer cells can avoid apoptotic cell death and often become resistant to treatments, representing a significant obstacle in modern oncology. A survivin suppressor, an imidazolium-based compound known as YM-155, is nowadays studied as an attractive anticancer agent. Although survivin suppression by YM-155 is evident, researchers started to report that YM-155 is also an inducer of DNA damage introducing yet another anticancer mechanism of this drug. Moreover, the concentrations of YM-155 for DNA damage induction seems to be far lower than those needed for survivin inhibition. Understanding the molecular mechanism of action of YM-155 is of vital importance for modern personalized medicine involving the selection of responsive patients and possible treatment combinations. This review focuses mainly on the documented effects of YM-155 on DNA damage signaling pathways. It summarizes up to date literature, and it outlines the molecular mechanism of YM-155 action in the context of the DNA damage field.

YM155 sensitizes HeLa cells to TRAIL-mediated apoptosis via cFLIP and survivin downregulation

Tumor necrosis factor-related apoptosis inducing ligand (TRAIL)-mediated apoptosis is a safe method for the treatment of various types of cancer. However, TRAIL therapy is less effective in certain types of cancer, including cervical cancer. To address this problem, a combinatorial approach was employed to sensitize cervical cancer at low dosages. YM155, a survivin inhibitor, was used at low dosages along with TRAIL to induce apoptosis in HeLa cells. The effects of the individual treatment with TRAIL and YM155 on apoptosis were assessed by propidium iodide assay. In addition, to validate the DNA damage exhibited by the combination treatment, the phosphorylation status of γH2A histone family member X was investigated by immunofluorescence and western blot analysis. TRAIL or YM155 alone had no significant effect on DNA damage and apoptosis. However, the TRAIL/YM155 combination triggered a synergistic pro-apoptotic stimulus in HeLa cells. The mRNA and protein levels of CASP8- and FADD-like apoptosis regulator (cFLIP), death receptor 5 (DR5) and survivin were monitored using RT-PCR and western blot analysis, respectively. This combinatorial approach downregulated both mRNA and protein expression levels of cFLIP and survivin. Further experimental results suggested that the combination treatment significantly reduced cell viability, invasion and migration of HeLa cells. Overall, the present findings indicated that the low dosage of YM155 sensitized HeLa cells to TRAIL-induced apoptosis via a mechanism involving downregulation of cFLIP and survivin. The results indicated the importance of combination drug treatment and reveal an effective therapeutic alternative for TRAIL therapy in human cervical cancer.

Cancer therapeutics using survivin BIRC5 as a target: what can we do after over two decades of study?

Survivin (also named BIRC5) is a well-known cancer therapeutic target. Since its discovery more than two decades ago, the use of survivin as a target for cancer therapeutics has remained a central goal of survivin studies in the cancer field. Many studies have provided intriguing insight into survivin's functional role in cancers, thus providing promise for survivin as a cancer therapeutic target. Despite this, moving survivin-targeting agents into and through the clinic remains a challenge. In order to address this challenge, we may need to rethink current strategies in order to develop a new mindset for targeting survivin. In this Review, we will first summarize the current survivin mechanistic studies, and then review the status of survivin cancer therapeutics, which is classified into five categories: (i) survivin-partner protein interaction inhibitors, (ii) survivin homodimerization inhibitors, (iii) survivin gene transcription inhibitors, (iv) survivin mRNA inhibitors and (v) survivin immunotherapy. We will then provide our opinions on cancer therapeutics using survivin as a target, with the goal of stimulating discussion that might facilitate translational research for discovering improved strategies and/or more effective anticancer agents that target survivin for cancer therapy.

Structure-Activity Relationship Analysis of YM155 for Inducing Selective Cell Death of Human Pluripotent Stem Cells

Despite great potential for regenerative medicine, the high tumorigenic potential of human pluripotent stem cells (hPSCs) to form undesirable teratoma is an important technical hurdle preventing safe cell therapy. Various small molecules that induce the complete elimination of undifferentiated hPSCs, referred to as "stemotoxics," have been developed to facilitate tumor-free cell therapy, including the Survivin inhibitor YM155. In the present work, based on the chemical structure of YM155, total 26 analogs were synthesized and tested for stemotoxic activity toward human embryonic stem cells (hESCs) and induced PSCs (iPSCs). We found that a hydrogen bond acceptor in the pyrazine ring of YM155 derivatives is critical for stemotoxic activity, which is completely lost in hESCs lacking SLC35F2, which encodes a solute carrier protein. These results suggest that hydrogen bonding interactions between the nitrogens of the pyrazine ring and the SLC35F2 protein are critical for entry of YM155 into hPSCs, and hence stemotoxic activity.

Quinone-Based Antitumor Agent Sepantronium Bromide (YM155) Causes Oxygen-Independent Redox-Activated Oxidative DNA Damage

Sepantronium bromide (YM155) is a small molecule antitumor agent currently in phase II clinical trials. Although developed as survivin suppressor, YM155's primary mode of action has recently been found to be DNA damage. However, the mechanism of DNA damage by YM155 is still unknown. Knowing the mechanism of action of an anticancer drug is necessary to formulate a rational drug combination and select a cancer type for achieving maximum clinical efficacy. Using cell-based assays, we showed that YM155 causes extensive DNA cleavage and reactive oxygen species generation. DNA cleavage by YM155 was found to be inhibited by radical scavengers and desferal. The reducing agent DTT and the cellular reducing system xanthine/xanthine oxidase were found to reductively activate YM155 and cause DNA cleavage. Unlike quinones, DNA cleavage by YM155 occurs in the presence of catalase and under hypoxic conditions, indicating that hydrogen peroxide and oxygen are not necessary. Although YM155 is a quinone, it does not follow a typical quinone mechanism. Consistent with these observations, a mechanism has been proposed that suggests that YM155 can cause oxidative DNA cleavage upon 2-electron reductive activation.

High-Throughput Screening of Myxoid Liposarcoma Cell Lines: Survivin Is Essential for Tumor Growth

Myxoid liposarcoma (MLS) is a soft tissue sarcoma characterized by a recurrent t(12;16) translocation. Although tumors are initially radio- and chemosensitive, the management of inoperable or metastatic MLS can be challenging. Therefore, our aim was to identify novel targets for systemic therapy. We performed an in vitro high-throughput drug screen using three MLS cell lines (402091, 1765092, DL-221), which were treated with 273 different drugs at four different concentrations. Cell lines and tissue microarrays were used for validation. As expected, all cell lines revealed a strong growth inhibition to conventional chemotherapeutic agents, such as anthracyclines and taxanes. A good response was observed to compounds interfering with Src and the mTOR pathway, which are known to be affected in these tumors. Moreover, BIRC5 was important for MLS survival because a strong inhibitory effect was seen at low concentration using the survivin inhibitor YM155, and siRNA for BIRC5 decreased cell viability. Immunohistochemistry revealed abundant expression of survivin restricted to the nucleus in all 32 tested primary tumor specimens. Inhibition of survivin in 402-91 and 1765-92 by YM155 increased the percentage S-phase but did not induce apoptosis, which warrants further investigation before application in the treatment of metastatic MLS. Thus, using a 273-compound drug screen, we confirmed previously identified targets (mTOR, Src) in MLS and demonstrate survivin as essential for MLS survival.